Some of the most common causes of nail detachment include injury, skin conditions, fungal infections, medication, diseases and chemicals, according to National Institutes of Health. Nails are formed from dead cells, which means once a nail is detached, another grows in its place.
One of the main causes of a detached nail is injury. This often happens when a person knocks his toes on hard surface. Fungal infections and diseases may also cause the area around the nail to grow weak and eventually loosen the nail.
Some chemicals, such as acetone nail polish, contain very strong components that may lead to nail detachment. Some skin conditions, such as psoriasis, if left untreated may become severe and also cause detachment of nails.